Many satellites and other spacecraft, as well as some terrestrial stationary and vehicle applications, such as seagoing vessels, can include one or more energy storage flywheel systems to provide both a backup power source and to provide attitude control for the vehicle. In such systems, each flywheel system is controlled and regulated to balance the electrical demand in the vehicle electrical distribution system, and may also be controlled in response to programmed or remote attitude (or torque) commands received by a main controller in the vehicle.
Many energy storage flywheel systems include one or more components that are rotationally mounted within a housing assembly. These components, which may be referred to as the rotating group, include, for example, an energy storage flywheel, a motor/generator, and a shaft. In particular, the energy storage flywheel and motor/generator may be mounted on the shaft, which may in turn be rotationally mounted in the housing assembly via one or more bearing assemblies. In many instances, the shaft is rotationally mounted using one or more primary bearing assemblies, and one or more secondary, or back-up, bearing assemblies. For example, in many satellite and spacecraft applications, the flywheel system may include one or more magnetic bearing assemblies that function as the primary bearing assemblies, and one or more mechanical bearing assemblies that function as the secondary bearing assemblies.
When a flywheel system is being transported from one location to another for testing and/or installation into an end-use system, the magnetic bearing assemblies are not activated and, therefore, will not support the rotating group. Moreover, when a flywheel system is installed in a satellite or other spacecraft, the magnetic bearing assemblies are not activated during the launch of the satellite or spacecraft. Thus, the magnetic bearings will also not provide support to the rotating group under these conditions.
During both of the operational events described above (e.g., transport and launch), the flywheel system may be subjected to various forces and vibrations. However, in many instances the secondary bearings are not constructed or configured to adequately support the rotating group against the vibrations and forces the flywheel system may experience during these events. As a result, the rotating group can be damaged during these operational events, which can shorten the effective life of the flywheel system and/or can increase system costs. To reduce the likelihood for damage during transport from one earthbound site to another for testing and/or installation, a flywheel system may be partially disassembled before transport, and then reassembled upon arrival at it destination. This operation can be time-consuming, and can undesirably add to overall system costs.
Hence, there is a need for a system and method for supporting the rotating group in an energy storage flywheel system during flywheel system transportation and/or launch that addresses one or more of the above-noted drawbacks. Namely, a system and method that supports the rotating group during transport and/or launch that reduces the likelihood for damage to the rotating group and/or does not rely on partial system disassembly and reassembly and/or reduces overall system costs. The present invention addresses one or more of these drawbacks.